package work.zhengyun.demo.nio.groupchat;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.charset.StandardCharsets;
import java.sql.SQLOutput;
import java.util.Iterator;
import java.util.Scanner;

/**
 * @Author: zhengyun
 * @Email: 574860631@qq.com
 * @Date: 2021/3/24 14:37
 */
public class GroupChatClient {
    //定义相关的属性
    private  final  String  HOST = "127.0.0.1";//服务器的IP
    private  final int PROT = 6667;//服务器端口
    private Selector selector;
    private SocketChannel socketChannel;
    private String username;
    //构造器，完成初始化工作
    public GroupChatClient() throws IOException{
        selector = Selector.open();
        //连接服务器
        socketChannel = socketChannel.open(new InetSocketAddress(HOST, PROT));
        //设置阻塞
        socketChannel.configureBlocking(false);
        //注册
        socketChannel.register(selector, SelectionKey.OP_READ);
        //得到username
        username = socketChannel.getLocalAddress().toString().substring(1);
        System.out.println(username+"is ok...");
    }
    //向服务器发送消息
    public void  sendInfo(String info){
        info = username +"说："+info;
        try{
            socketChannel.write(ByteBuffer.wrap(info.getBytes()));

        }catch (IOException e){
            e.printStackTrace();
        }
    }
    //读取从服务器端回复的消息
    public  void readInfo(){
        try{
            int readChannels = selector.select();
            if(readChannels>0){
                Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();
                while (iterator.hasNext()){
                    SelectionKey key = iterator.next();
                    if(key.isReadable()){
                        //得到相关通道
                        SocketChannel sc = (SocketChannel)key.channel();
                        sc.configureBlocking(false);
                        //得到一个buffer
                        ByteBuffer buffer = ByteBuffer.allocate(1024);
                        //读取
                        sc.read(buffer);
                        //把读到的缓冲区的数据转成字符串
                        String msg = new String(buffer.array());
                        System.out.println(msg.trim());
                    }
                }
                iterator.remove();//删除当前的selectionkey 防止重复操作
            }else {
                //System.out.println("没有可以用的通道");

            }
        }catch (IOException e){
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws Exception{
        //启动我们的客户端
        GroupChatClient chatClient = new GroupChatClient();
        new Thread(){
            public void run(){
                while (true){
                    chatClient.readInfo();
                    try {
                        Thread.currentThread().sleep(3000);
                    }catch (InterruptedException e){
                        e.printStackTrace();
                    }
                }
            }
        }.start();
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextLine()){
            String s = scanner.nextLine();
            chatClient.sendInfo(s);
        }
    }
}
